Amusement devices, such as marbles and the like, have traditionally been made from glass or ceramic materials. These materials may fracture or otherwise break during use. More recently, such items have been made from thermoplastic resins such as acrylic or polyester resins. A beneficial feature of manufacturing marbles and the like from such materials is that, due to the strength of the resin, a greater force is generally required to cause the article to fracture or otherwise break.
In order to increase the attractiveness of marbles, it has been known to colour a portion of the interior of the marble or otherwise encase an object within the article. For example, U. S. Pat. No. 4,116,439 (Chavarria et al) discloses a pool ball which may have encased therein a small cube, bottle caps or a disk. One disadvantage of these articles is that the inclusion of a large insert weakens the integrity of the article such that, under normal conditions of use, the article may fracture or otherwise break.
U.S. Pat. No. 4,214,753 (Haber et al) discloses a transparent article that may be used as a pool or billiard ball. According to this disclosure, Haber et al discloses a method of molding which assures bonding of the encapsulated portions with the resin of the sphere in such a manner as to minimize the risk of any cleavage planes which would result in shattering of the ball upon impact. (column 1, lines 59-64). A pool ball manufactured according to Haber et al includes a disk member which is positioned in a ring shaped holder, all of which is encapsulated in a resin. The holder is manufactured from a thermoplastic material which will mechanically and chemically bond with the resin. A characteristic of the thermoplastic material comprising the disk is that it swells slightly upon extended contact with resin. Bonding of the disk and ink to each other and to the resin thus results in an engraved characteristic for the symbols which are provided on the disk, the uncovered surface portions of the disk swelling slightly. The further bonding of the ring with the disk and resin results in a final sphere in which shock impacts are absorbed by the disk, ink and ring as well as the resin as though the entire sphere were homogeneous throughout (column 5, lines 15-25). However, the use of a separate ring-shaped holder has various disadvantages.